TY - GEN
T1 - Rapid startup of a PEM fuel cell from subzero temperature
AU - Jiang, Fangming
AU - Wang, Chao Yang
AU - Chen, Ken S.
PY - 2009
Y1 - 2009
N2 - Current-ramping strategy can be used for rapid startup of PEM fuel cells (PEMFC) from subzero temperatures. Via numerical modeling a series of parametric studies are performed in this work to explore the optimum parameter set for current-ramping cold-start. A PEMFC with standard cell thermal mass, 0.4 J/cm2/K, starting from -30°C is of primary interest in this work. It is found that either a small initial current density (100mA/cm2) combined with an intermediate ramping rate, or a relatively large initial current density (200 mA/cm2) in combination with a small ramping rate, can lead to successful self-starts if the membrane electrode assembly (MEA) is sufficiently dry prior to startups. However, the current-ramping cold-start with a too small initial current density (≤50mA/cm2) is found to shut down with whatever the current-ramping rate. More rapid self-start can be achieved by increasing the initial current density, which is limited mainly by the initial water content in the MEA. Hence, keeping the MEA mildly hydrated prior to cold start can be favorable to the rapid current-ramping startup. This is particularly important for the rapid startup of next-generation PEMFCs with reduced thermal mass. Results show that a PEMFC with 0.2 J/cm2/K thermal mass and a relatively wetted MEA can be successfully started up from -30°C in a few seconds if it is possible to draw the current density as high as 1 A/cm2 right from the beginning.
AB - Current-ramping strategy can be used for rapid startup of PEM fuel cells (PEMFC) from subzero temperatures. Via numerical modeling a series of parametric studies are performed in this work to explore the optimum parameter set for current-ramping cold-start. A PEMFC with standard cell thermal mass, 0.4 J/cm2/K, starting from -30°C is of primary interest in this work. It is found that either a small initial current density (100mA/cm2) combined with an intermediate ramping rate, or a relatively large initial current density (200 mA/cm2) in combination with a small ramping rate, can lead to successful self-starts if the membrane electrode assembly (MEA) is sufficiently dry prior to startups. However, the current-ramping cold-start with a too small initial current density (≤50mA/cm2) is found to shut down with whatever the current-ramping rate. More rapid self-start can be achieved by increasing the initial current density, which is limited mainly by the initial water content in the MEA. Hence, keeping the MEA mildly hydrated prior to cold start can be favorable to the rapid current-ramping startup. This is particularly important for the rapid startup of next-generation PEMFCs with reduced thermal mass. Results show that a PEMFC with 0.2 J/cm2/K thermal mass and a relatively wetted MEA can be successfully started up from -30°C in a few seconds if it is possible to draw the current density as high as 1 A/cm2 right from the beginning.
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U2 - 10.1115/FuelCell2009-85029
DO - 10.1115/FuelCell2009-85029
M3 - Conference contribution
AN - SCOPUS:77953734192
SN - 9780791848814
T3 - Proceedings of the 7th International Conference on Fuel Cell Science, Engineering, and Technology 2009
SP - 289
EP - 297
BT - Proceedings of the 7th International Conference on Fuel Cell Science, Engineering, and Technology 2009
T2 - 7th International Conference on Fuel Cell Science, Engineering, and Technology 2009
Y2 - 8 June 2009 through 10 June 2009
ER -